Fluid-pressure switching device.



R. V. CHEATHAM.

FLUID PRESSURE SWITCHING DEVICE. APPLICATIO\N FILED JULY 14. 1914.

Patented Apr. 4, 1916.

a SHEETS-SHEET i.

R. v. CHEATHA M. FLUID PRESSURE SWITCHING DEVICE. APPLICATION FILED JULY I4, I9I4- 1 1773602. Patented Apr. 4, 1916.

. 3 SHEETS-SHEET Z- FLUID PRESSURE SWITCHING DEVICL. APPLICATION FILED JULY 14, 1914.

V. CHEATHAM.

Pateiited Apr. 4,1916.

3 SHEETS-SHEET 3.

ROBERT V. CHE-ATI-IAM, OF ST. MATTHEWS, KENTUCKY.

FLUID-PRESSURE SWITCHING DEVICE.

Specification of Letters Patent.

Patented Apr. 4, 1916.

Application filed July 14, 1914. Serial No. 850,956.

To all whom it may concern Be it known that 1, ROBERT V. lHEAT- HAM, a citizen of the United States, and a resident of St. Matthews, county of Jefferson, and State of Kentucky, have invented a new and useful Improvement in Fluid- Pressure Switching Devices, of which the following is a specification.

The object of my invention is to improve a switch of the type shown in my Patent No. 93-l,138, dated September H, 1909, which object is accomplished by my invention, one embodiment of which is hereinafter set forth.

For a more particular description of my invention, reference is to be had to the accompanying drawings, forming a part hereof, in which- Figure 1 is a plan view of a track provided with my improved switch. Fig. 2 is a sectional view of the track box, taken on the line 2-2 of Fig. 3, looking in the direction of the arrows. Fig. 3 is a plan view of the track box with cover removed, the derailer and connections. Fig. Tis a sectional view of a portion of the ram which actuates the switchpoint. Fig. 5 is a plan view of a pump used for actuating the ram. Fig. 6 is a longitudinal section of the pump. Fig. 7 is a sectional view of the packing and incidental parts.

Throughout the various views of the drawings, similar reference characters designate similar parts.

In Fig. 1 are shown two tracks crossing each other at right angles, one of which, the track 1. may be a railroad track, and the other, the track 2, an ordinary trolley track, with a suitable derailer 3, of the conventional kind. The derailer 3 may be of any suitable form, but in the embodiment shown consists of a switch point rail 1 and a block 5 which are connected to suitable spur rails 6 and 7 which extend far enough to derail the car and no farther, in the event that the motor-man attempts to proceed when the derailer is set against him. The derailer is actuated by suitable mechanism concealed in the track box 8, which is actuated through a pipe, 9, which runs under the railroad track 1 to a pump 10 which is placed in any convenient position, the idea being that the conductor must first cross the track so that he will have every opportunity to look both ways before actuating the pump so as to throw the derailer into an operative position.

While the pump in the embodiment of my invention herein shown actuates the derailer, it is true that instead of a switchpoint rail of a derailer, the actuating mechanism may operate a signal, or anything else at a distance from the pump, such as crossing gates, etc. It is also true that by virtue of the arrangement hereinafter clescribed the derailer will be properly actuated regardless of any expansion or contraction due to temperature changes and -without regard to any amount of water that may find its way into the exposed parts of the apparatus, as such Water cannot get beyond the exposed parts, although no packing box is employed, or other means for expelling such water.

T he pump mechanism.-The pump 10 can best be understood from Figs. 5, 6 and 7. It is connected to the pipe 9 at the bottom of a casing 11 which has a projecting cylinder 12 which extends down into the earth and contains an upwardly extending bushing 13, which runs Well into the interior of the casing 11, it being understood that this casing 11 is buried in the ground 14 and substantially as shown in Fig. 6, although it may be more or less exposed, if desired. The preferred embodiment is shown. On the interior of the casing 11 and parallel with the bushing 13, and concentric therewith, is a collar 15, which is preferably made integral with the casing 11. This casing, is closed at its upper extremity by means of a suitable cover 16, held in place by suitable cap screws 17, and this cover has an upwardly extending cylindrical projection 18, which is on the same axis with the bushing 13, and projection 12 and fits against the-plunger rod 19 with a snug sliding fit, the lower end of this rod having a corresponding fit in the bushing 13, in a manner which will be described below, this fit being caused by a suitable packing which will be described below.

The top of the plunger rod 19 is surrounded by a flanged cap 20, which is large enough to surround the projection 18, without striking the same, and. this cap has a suitable roughened upper surface 21, so that the plunger may be driven downward by the conductor of the car when he places his foot on this roughened surface and presses. Normally, this plunger 19, is kept at the upper limit of its movement by a coiled spring 22, which surrounds the bushing 13 and lower end of the plunger 19 and presses against the second cap 23 which is fixed to the plunger 19, by means of a pin 24, or other suitable means, this spring 22 resting at its upper end against an annular collar 25 on the lower surface of the top of this cap 23. This cap 23 is made substantially as shown in Fig. 6, that is, large enough to in close the collar or bushing 15 with which it is concentric. The top of this cap 23 is sur mounted by a coiled spring 26, which rests against the lower surface of the cover 16, which is shown in Fig. 6, so as to prevent the plunger 19 from rising too much and to cushion the upper limit of its movement so that there will be no collision with the cover 16. It is apparent from what has been shown and described that the springs 22 and 26 act in opposition and are in equilibrium with the parts as shown in Fig. 6, or in substantially this position. The lower end of the plunger 19 is provided with a packin 27, which will now be described. Near its lower end the plunger 19 is divided into two parts, one the main stem 28 and the other the lower portion 29, and these parts are connected by screw threads, as shown in Figs. 6 and 7, although the parts are slightly recessed near where they come together so as to make room for opposed leather cups 30 and 31 which are separated by a washer 32 so that a tight joint is had no matter whether the plunger 19 rises or falls, this joint being within the bushing 13 which is perforated at 33 near the lower end of the part 29 and below all packing. Out of abundant caution it is preferable to provide the lower part 29 with an annular groove in which is placed a suitable packing.

The )2'pes.The pipe 9 which connects the pump 10 with the ram 8 may be provided with as many unions, joints and elbows as desired, as its length is absolutely immaterial. It is preferably made with a uniform cross-section which is sufficiently large to permit a flow of liquid from the pump to the ram and is proportioned to the size of these two instruments. For all the usual conditions of service a linch pipe is found ample.

T he mm.'The ram 8 is shown in Figs. 2, 3 and 4, and is provided with a suitable casing 35 surmounted by a suitable cover plate 36 that rests on a suitable flange 38 close to the top of the casing 35. It is provided with a slot 39 adjacent to the derailer 3 so that the switchpoint rail 4 can. be connected with the interior of the casing 35 by means of a projection 40 which extends far enough to engage the mechanism connected with the ram, in a manner which will be described below. The casing 35 has an inclined partition 11 which is curved and flanged at 42 on each side of the curved portion, to receive the cylinder -13 of the rain, to the interior of which the pipe 9 is connected so that oil may flow freely either way from the pump to the interior of the ram.

The cylinder 43 of the ram is closed at its upper extremity by means of a suitable screw plug H resting on a packing 45, or other suitable means, and at its lower end it runs into an integral trough or trap 46, which is preferably shaped as shown in Figs. 2 and 3. so as to hold mercury 47 on each side of the partition 48 which extends well below the surface of the mercury so as to divide the mercury into two parts, one on each side of the partition 48, and this partition extends far enough below the surface of the mercury to form a seal or trap. A bell crank lever 49 is fulcrumed on a suitable pivot 50, mounted on ears 51 on the trap -16. Suitable cotter pins-52 hold the pin 50 in place, or it may be held in any other suitable way. The projection 10 is connected to the bell crank lever 49 by means of an eye bolt 53 which has a ball and socket connection with said lever and an eye connection with a lug 54 that extends downwardly from the projection d0. Bolts or cotter pins or other suitable means 55 are placed above and below the eye of the link 53 so as to permit this link to swing slightly in a vertical plane under the action of the bell crank lever 49. The projection 40 has a second projection 56 which extends laterally in a horizontal plane to near the casing 35 where this projection is perforated to receive a coiled spring 57 which has its other end secured to a bolt 58 fixed in a side wall of this casing It is to be understood that this casing may be secured by being embedded in concrete or otherwise, if desired.

The other end of the bell crank lever 49, that is, the inner end which is close to the ram cylinder 43, is provided with a suitable socket which receives a corresponding ball 59, on a rod 60 which has its upper end rounded so as to fit with a snug journal fit against the piston 61 of the ram. This piston 61 slides freely with a snug fit against a. bushing 62 which is fixed in the cylinder 43. This piston 61 has a normally open passage 63 which runs to its interior from the hollow plug 6+1 which is screw-threaded therein. This plug 6+1 has a flange 65 which presses a leather cup washer 66 against the piston 61 so that this washer is held against the bushing 62 with a tight fit whenever fluid pressure is applied to the upper surface of the piston, but not otherwise.

The passage 63 contains a coiled spring 67 which runs upwardly through a hollow valve stem 68 which is provided with a flange or collar 69 at its lower end, to limit its movement against the plug 64, and at its upper end it is provided with a suitable packing 70 held in place by a nut 71 which packing may rest in a corresponding seat at the top of the plug 64 and which normally rests off this seat under the action of the spring 67, so that a complete oil passage is normally open from the top of the mercury 47 through the pipe 9, bushing 13 and open ing 33 to the interior of the bushing or col- .lar 15. Any suitable fluid maybe used over the mercury, but oil is preferred because it 15 will not freeze or cause rusting. This oil is placed in the apparatus so as to reach above the level of the opening 33 and preferably not above the top of the bushing 15. If any small amount of moisture or dust should getbeyond the cap 16 and between it and the plunger 19, it will accumulate outside of the bushing 15 where it will settle, in a sediment pool of oil in the casing 11 where it can do no harm. It is believed that under normal conditions no water will reach even as far.

as this. I

0perati0n.-In view of the foregoing, the operation of my improved device will bereadily understood. Assuming that a conductor has observed that the track 1 is clear.

so that a car can proceed on track 2, he

places his foot on the cap 20 of the pump 10 and forces the plunger 19 downwardly. This forces liquid out of the bushing 13 until the perforation 33 is passed and then further escape of liquid is prevented and the liquid is forced from the bushing 13' and projection 12 into the pipe 9 whence it flows into the interior cylinder 43 of theram 8.

The pressure on the packing 70 causes the valve to close on the hollow plug 64 and then the piston 61 is forceddownwardly so as to cause a corresponding movement of the bell crank lever 49 through the rod 60, and this bell crank lever in turn forces the rod 53 against the projection 54 so as to-cause the L switch-point rail 4 to be thrown, so that the -car will not be derailed but may go straight ahead when passing over this switchpoint rail. Whenlthe car has passed, the conductor removes his foot from the projection 21 of the cap 20 on the plunger 19 and then the spring 22 causes this plunger to rise to its normal position, as shown in Fig. 6, and si- 55. multaneously the spring 57 restores the rail 4 to the derailing position and the mercury 47 is restored to equilibrium and forces any surplus oil out between the packing 7 0 and the plug 64 through the passage 63, as is ob'- vious. The presence of the mercury 47 prevents any water that may get into the interior of the casing 35 from getting beyond the upper surface ofthe mercury in the exposed part of the cup 46 where this water may floatuntil dries out without doing any harm. If mud is in this water the sedi- I ment will remain on the mercury after the water has evaporated and be harmless. It Wlll be noted that when the passage through 4 the piston 61 is open, as it is under normal.

conditions, more or less oil can float from the mercury to the exterior of the bushing 13 without any obstruction whatsoever, so that any expansion or contraction due to changes in temperature may be taken care of without in any Way afiecting the action of the apparatus. e 7

While Ihave shown and described one embodimentof my invention, itis obvious that it is not restricted thereto but is broad enough to v cover all structures that come within the scope ofthe annexed claims.

Having thus described my invention, what I claim is 1. In a device of the class described, a pump, a ram, connections between the two, a mercury trap and means for communicating the motion of the ram plunger through said mercury trap whereby the ram is pro tected from the entrance of water or the leakage of oil by said mercury trap.

2. In a device of the class described, pump, a ram, connections between said pump and ram, a mercury trap with a bell crank lever having one arm therein and a connection between said ram and arm whereby said ram moves said bell crank.-

lever through the mercury in the trap.

3. In a device of the class described, a ram, a casing supporting said ram and in ed in said casing and connected to the cylinder of. the ram, and mechanism partially immersed in said mercury and a piston rod connecting said mechanism and said ram under the'surface of the mercury.

4. In a'device of the class described, a

l1 which it is mounted, a mercury trap mountmercury trap with mercury therein, mechanism extending into said mercury and below the top surface of the same, a cylinder with its axis striking the surface of the mercury at an angle, a plungerin said cylinder adapted to shift in said cylinder above said mercury and passages and a valve in said plunger, and a rod connecting said Ill plunger and mechanism so that the plunger will act in oil and the mechanism will opierate partially immersed in mercury whereby the admission of water to the plunger orthe egress of oil from the plunger is pre vented by the mercury.

. .5. In a device of the class describedya pump having a casing, a perforated bushing mounted in said casing,

' suitable packing mounted in said bushing and a collar. and opposed springs in said casing cooperating with said plunger.

a plunger with 6. Ina device of the class described, a

a perforated busha plunger with pump having a casing, ing mounted 1n sald casing,

suitable packing mounted in said casing and bushing and opposed springs in said casing cooperating with said plunger.

7. In a device of the class described, a pump having a casing, a perforated bushing mounted therein, a plunger with suitable packing mounted in said casing and bush ing and a collar surrounding said bushing and in said casing.

8. In a device of the class described, a pump having a casing, a perforated bushing mounted in said casing, a collar in said casing surrounding said bushing and a hood fixed to said plunger and concentric there- Withand surrounding said collar.

9. In a device of the class described, a pump having a casing, a perforated bushing mounted therein, a collar surrounding said bushing, a plunger mounted in said casing'and bushing, a hood fixed to the said plunger and surrounding said collar, and a spring whereby the plunger is held normally in an elevated position and may be operated against the action of said spring.

10. In a device of the class described, a pump having a casing, a perforated bushing mounted in said casing, a plunger mounted in said casing and bushing, a cover on said casing, provided With a tubular projection and a cap on said plunger surrounding said tubular projection.

11. In a device of the class described, a pipe, means for forcing a fluid through a pipe, a ram connected to said pipe and provided with an open end extending to a mercury trap, power transmitting means and mechanism passing through the mercury trap connecting said ram and power transmitting means.

Bonnier v.

CHEATHAM. 

